Born in a shirt? Give it to the patch for the heart!
Researchers from Keio University in Japan, working under the leadership of Hiroko Tsuji, have proposed another source of ethical, universal and fairly affordable stem cells – the amniotic membrane, the germ shell, which sometimes sticks to the body of children "born in a shirt." Unlike the umbilical cord and placenta, the amnion was still considered "medical garbage".
Scientists managed to transform mesenchymal stem cells of the human amnion into cardiomyocytes: about a third of the resulting cells showed the ability to spontaneous contractions. The authors note that this result significantly exceeds the potential of mesenchymal stem cells of bone marrow or adipose tissue to form heart muscle cells.
In experiments on rat models, the introduction of such mesenchmal cells into the myocardial infarction zone, two weeks after modeling this disease, increased the functional ability of animal hearts by 34-39%, while the functioning of the hearts of control group rats continued to gradually deteriorate. The introduction of mesenchymal cells into the heart of rats immediately after a heart attack reduced the scarring zone by 13-18%. At the same time, the transplanted cells did not cause the development of immunological rejection reactions even without the use of immunosuppressive drugs and survived in the hearts of recipients for more than four weeks.
The lack of an immune response to the transplanted cells, apparently, is due to the fact that the amniotic membrane is a barrier between the woman's body and the developing embryo. In order to protect the embryo, which is essentially a complex of foreign tissues for a woman's body, from the mother's immune system, the amnion cells do not synthesize proteins used by the immune system to identify foreign tissues. This means that the clinical use of mesenchymal stem cells of the amniotic membrane eliminates the need for preliminary selection of an antigen-compatible histocompatibility complex of the donor, as well as subsequent administration of toxic immunosuppressive drugs.
Experts also suggest that mesenchymal stem cells of the amniotic membrane can be differentiated not only into cardiomyocytes, but also into cells of other types. They emphasize that there is still a lot of work ahead, and are currently repeating their experiments on larger animal models and working on methods to increase the number of heart cells formed by mesenchymal stem cells of the amniotic membrane.
The results of the work are published in the journal Circulation Research in the article "Xenografted Human Amniotic Membrane-Derived Mesenchymal Stem Cells Are Immunologically Tolerant and Transdifferentiated Into Cardiomyocytes".
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on ScienceDaily: New Source of Stem Cells Form Heart Muscle Cells, Repair Damage.
02.06.2010